The present invention relates to micro control devices having the capability of communicating with an external device through a communication port and, more particularly, to postage meters, and like devices, having a micro control system enclosed in a secure housing wherein the micro control system is suitable for communicating secured or unsecured information through a communication port between the meter and the external device.
It is customary to provide a fully featured meter with a number of communication ports, e.g., a port for secure communication between the meter's secure printing and accounting system with an external device, such as a echoplex scale, and one or more ports for non-secure communication, such as, with a computer. An echoplex scale refers to a scale with the ability to set the meter's posting amount using a secure communication protocol, such as described in U.S. Pat. No. 4,525,785, entitled Electronic Postage Meter Having Plural Computing Systems. An example of unsecured communication is the use of a standard RS232 protocol for the printing of unsecured departmental account information by an external printer.
Providing a meter with full communication capability presents a cost consequence to the user, which the user, in many instances, wishes to defer until such time as the user can cost justify the additional capabilities and features. The user would also like to obtain the deferred features at an incremental cost.